Crystal and molecular structure of 1-(2-aminoethyl)biguanide-isothiocyanato-copper(II) thiocyanate

The crystal structure of 1-(2-aminoethyl)biguanide-isothiocyanato-copper(II)thiocyanate, Cu(aebg)(NCS)] (SCN) (aebg = NH₂. CH₂. CH₂. N=C(NH₂). NH. C(NH). NH₂) has been determined and refined by Fourier methods using three-dimensional X-ray data collected on a Weissenberg automatic diffractometer. The unit cell parameters are:a = 11·41(2),b = 8·81(2),c = 7·45(2) Å; = 87·6° (2); = 67·2° (2); = 70·1° (2);Z = 2.Assuming space group P¯1, the structure was refined down toR = 8·5 %. The coordination around Cu is slightly distorted square planar and concerns three N atoms from the aebg ligand (Cu-N = 1·988(8), 2·019(7), 1·963(5) Å) and the terminal N of an isothiocyanate group (Cu-N = 1·941(5) Å). Two unsymmetrical, long interactions (Cu-N = 3·367(7) and 2·947(7) Å), with the N atoms belonging to two NCS groupstrans with respect to the coordination plane, complete the coordination to a distorted octahedron. In the aebg ligand the double bonds are localized on the C-N groups, whose nitrogen atoms coordinate to the metal.This work was carried out with the aid of financial support from the Consiglio Nazionale delle Ricerche, Roma.